For security reasons, you may want to clear the pagefile.sys when you shutdown the system. Edit:
HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession ManagerMemory Management
Add Value name ClearPageFileAtShutdown as type REG_DWORD. The default is 0. When you set it to 1, inactive pages in the pagefile.sys will be filled with zeros. Some pages can not be cleared as they are active during shutdown.